Heat control valve



Jan. l, 1935. s. w. sPARRow 1,986,542

' HEAT CONTROL VALVE Filevd Sept. 8, 1932 `2 Sheets-Sheet 1 Jan. 1, 1935. j s. w. sPARRow 1,986,542

HEAT CONTROL VALVE Filed sept. s, 1952 2 sheets-sheet 2 40 2a 29 l' ll Patented Jan. 1, 1935 l y, A di l HET ooNrRonvALvE 1f StanwoodWrSparrow; Y i to The! Studebaker South `BuendlInd., assignor A CorporationrSouth Bend, c

` ilnd., a corporation of New Jersey This invention relates to control meansfor the heat regulating valve foruthe intake manifold of aninternal combustion engine and has for its principal object` the provisionof control "means for such a heat regulating' valve which is fully automaticin operation, n n n A further` object lies in theprovisionof ther- `mostatic control means in addition to gravity or flow controlled means forregulating the application of heatto the intake manifold. l i l A still `further object lies in the provision of Ameans of the `character described `whiclilis sim- "ple and economicaltosmanufacture andfapplyan'd which willnotreadily getoutof orderin use.

Otherobjectsand advantages ofthe' invention will appearas the description proceeds.

i` The drawing forming a part of this application shows a preferred mechanical embodiment of the idea ofthe invention and two modified construe` tions by means of ,which the, idea of the invention `may ber satisfactorilycarried out. `The drawing,k

however,` is for the `purpose ofillustration "only `-and is not to be considered as limiting the inven- Ri-*FigureS is a y y thev heat controlling valve in position to prevent tion, the slcopeof which is to be measured'entirely` bythe scope of the sub-joined claims.

.Inthedrawings'r V l Figurei is a vertical elevationalfview of afragmentary `portionofan exhaust manifold and of affragmentary portion of'anintake manifold for an internal combustionengine, Showing the device of the inventionl 'applied'thereto. w

f lFigure 2 isa vertical sectional viewf on the line` 2?-2 of Figure 1,fshowing the heat controlling valve in position to apply heatto the intake .mani` fold. M A l r" View similar to Figure 2 showing the'application of heat tothe intake manifold.

ladditiona tion. N .y

Referring to the drawings in detail'and par`` Figure f4 is a Vertical elevational view of a someplied to -a c portion of the exhaust manifold-of an internal combustion engine, acportionvV of thein- IVtake manifold of the engine being shown in sec- Figure 5 is a viewsimlarto Figure 4 showing an l modification' of the devicenloi the inventicularly to Figurel, the numeral generally indicates the exhaust manifold of` an internalv combustion engine. This exhaust manifold is provided with a" `centrally located downwardly y extending outlet channed v12 particularly illus` n trated in Figures `2 andv 3" which lopens into a "Y-shaped chamber 13 provided with an upwardly Application september 8,1932, sriaindeaans v t l 13 claims. (o1. 12g-+122) `opening branchlf and a downwardly opening outlet channel 15 to the bottom` of `which is attached a fiange 17 towhich` an exhaust gas con- 5 buretoryla fragmentary portion of which is indicated at"in Figure 1., is attached. `'chamber 22 is provided interiorly' thereof withha" :pair

of vertical "cylindrical chambers or risersA 264 and 27; illustrated in Figures 2 and 3; whi'chfleadffrom the `-`cylinders of the internal combustion engine.

The risers" 26 and? 27 are separated from" "each vother by an intermediate wall ,'lljand are sur-V rrounded` byan `exterior`wall31g outeri wall c A 32 surroundslthewall 31 in spaced relationtherefc -toj-and extendsfmm the bottomffthe flange 24 vto the bottomfof the chamberl`22whereit i'sfprovided with a iiange 34whichlcooperates'with a ,c r`iiza,n`ge"35` formed atthe top of the branch 14`it`o bottoms" of 'the"intake headers 28V and 29 "are ."closedyby a walll"37 which formsjafcontinuatio'n dfthefwalls 30 `and31"sol that the risers 26 and the Wall'31 andthe bottom wall 37 in-such a 'mannei" fas to provide an annular `chamber 33 entirely surrounding "the risers'v 27 and 26` and the portion', of the headers 23 and29 contained 'withinfthechamber 22;,11 l what modied form of the invention shown apA The bottom"wall"3'7'is"provided with a cylindrical bbltv 139 which 'eXeldSeIitlauy belleth spectively 'into' the `boref38fto provide anopenf ing from the bottom ofthe `headersfto` the "exterior ofthe intake `manifoldsojthat any"gaso` line condensed `in the headers 'or injected-therein` by over-forming and oodingthe'downdrafc Carf- -buretor= 25 may be drained'away by' theldrain fitting "plug` 4 2.,` The bottomwall 37 is` also pro` vided` with adownwardly'e'xtending n" or partition 46 whichexten'ds tothe plane ofthe lower surface'` of the ange 34 and-"extends across `the flange 34.

chamber 22 in a direction longitudinally of the intake manifoldA and substantially bisects the opening in the chamber'22 surrounded by the The branch 14 is provided with a diametrical partition 48 which coincides with,

`and forms a continuation of the partition 46.

These two partitions 46and 48 constitute a baffle generally indicated at.49 which divides the.t upper portion` ofthe branchk14 into twosubstantially equal' portions. A gasket 50 is interposed between the flanges 34-and 35 and a portion of this gasket extends between the partitions 46 and 48 to provide a gas-tight seal between the!chamber` 22 and the branch 14.

A transverse pivot pin r52 extendsgthrough ythe downwardly projecting portion 13 of the n.exhaust-- j manifold at l approximately the point where a ,Y

continuation of the baffle 49 intersects the vertical plane along which the branch 11i-joins the-.

branch 12 to constitute the Y-shapedportion 13.

This'pivotpin- 52carriesinteriorly of the down- .of the baille 49 and the curved lower end 56 of fthe; valve substantiallyfcloses the i lower end'. of

fthe-exhaust Cheri-M142 Causing. ,the ,exhaust gasesgto flow upwardly through the portio1f1.of the .branchylfi' ,adjacent to the channel 12 through vtherannular.V chamber 33 land out through thev portionofqthe braneh14remote from the rchannel 412,; and then through, the bottom portion. 15 of theexhaust manifold to the; exhaust gas conduit, not illustrated-3. .-1 l.. l i xltwill beobserved that. inthis operative posiy tionjof the valve 54, the exhaust gas iowing as .indicated by the arrow on Figure 2 will Vflow around .therisers 26. and-27 and the portionsof thehead-A ersj28- and 29 contained inr the chamber 22and apply heat thereto/to heatthe4 fuel Vcharges being .drawnzthrough the risers and headers from-the carburetor tothe cylindersv of -an internal combustion vengine to which the manifold isapplied. f ,In the operative position of the valve l54 illus- -trated in Figure 3Y which will hereinafter be re,- ferredto as the open position, the valve isso positioned-'as to form a substantial continuation of the wall 60 of-y the exhaustchannel 12 and to form vaclosurefor the lowerl end of the branch 14. In this position of the va1vethe exhaust gases flow straight through the exhaust channel 12 vand ltlfirough thelower portion 15jcf `the exhaust manifold to the exhaust conduit and do not enter the `annular chamber 33, in which case-there is no heating ofthe fuel charge by the exhaust gases.

The-.movement of the valveg54 from lone to the othergof its operative positions is brought about .aJ.S'.f01..10Vi.Sy f `An arm 62 ishop-rotatably mounted upon the end;- ofthe` pivot pin 52 which extends through .the ,portion 13 of `the exhaust manifold, and a .weight 64 is formed upon the outer end ofthe arm-.62.1. r-Iheigravitational eifectof the .weight 64 .tendsgto move the'valve 54 to the operative position illustrated; in Figure 2, in which position the ,.curved lower'end 56 o f the valve 54 closes'the di- .rect loutletof the exhaust gases. When the internal combustion engine is operatingat areducedspeed and the ow of exhaust gases therefrom is comparatively small, the force of the exhaust gases impacting against the curved end 56 of the valve y54 will not be sufcient to raise the weight 64 and the exhaust gases will be caused to flow upwardly through the branch 14, through the annular chamber 33 and then downwardly to the branch 14 before leaving the exhaust manifold. As-the engine is speeded up and the flow ofexhaust gases becomes greater, the force of the exhaust gases impacting against the curved errd 56 of the valve 54 will gradually overcome the effect of the weight 64 and will move the valve -54't'o the operative position illustrated in Figure l 3,. in which position-the exhaust gases flow di- .rectlyoutl of the intake manifold and do not circulate to the chamber 33.

AV pair of abutments 66 and 67 are formed on the portion 13 of the exhaust manifold, or as illustrated in; Figures 2 and 3, are formed on a plate 68 which is secured to the exhaust manifold by boltsi70 and .71. 4A stop member '73 is secured to "the arm 62' by vmeans of a screw '74 and the contact of this stop m'ember..73 with the abutments 66 andSG'Ylimitsthe,movement oi thevalve 54 to its two operative positions.. .f i

A gravity or how-control valve as kdescribed ,above'has been found to'greatly improve the performance of an internal combustion engine to whichv .it-is applied. Ordinarily the engine will run smoothly and will not miss at relatively high 'speeiifand itis only at low engine speed. that the fapplicationoff heatnto the manifold' to increase "the evaporation of the fuelris'necessary. It has v been found, however, that there-are cases in which the engine' will notV run. smoothly even at high speed unless exhaust gas heat is applied to the firing charge las it passes through the intake manifold; as'wh'enr the "weather is extremely cold or Vwhen the vengine hasffnst been started. In order toovercome this difficultyand further improve .the performancefof the engine, applicant has provided atherm'ostatic control to act in combina- -tionwith' the gravity or :flow-control of the heat controllingvalve 54.

As illustrated'ingFigures 2 'and 3; the portion 13 of the exhaust manifold ,or the'platel68 attached thereto is provided with a laterally offset portion or abutment SO-having a horizontallower surfaceSL This portion-80V is preferably. cast integrallywith the exhaust manifold or with the plate attached thereto and is braced to the exhaust manifold or the plate'by vertical ribs 83 `and 84. A flat bi-metallic Y.thermostatic element -85 is securedy to thelower surface of the portion 80 as by screws 87 and 88 and provided at its outer or'free end1with`a hook 90 suitably secured .thereto -as by rivets1'91'.l The'weight'64 is provided in the lower portionI thereof with a slot 93, into which ythe hook 90 projectswhen the weight is in its lowermostposition. pin 95 extends transversely through the slot 93 and isV surrounded by a sleeve -96 rotatablymounted thereon, the pin and sleeve beingso positioned that when the weight 64 is in its lowermost position. andwhen the thermostatic bar y85 is straight,'the hook 90 lwill engage the sleeve 9'6`and prevent the weight 64`from rising to change the position of the valve 54.

The .bar S5is so constructed that itis straight nas. illustrated in Figure 2 when cold.v As the temperature o f the bar increases, it bends so that the free end vthereof and the hook 90 are moved downwardly-.torelease.the sleeve 96 and pinl 95 as. illustrated inQFigure 3thereby releasing the weight Vand-permitting it to moveupwardly there- "insegne by "permitting the valvebe` to assume the Fomlthefabove description it willbe observed that when the'engine and the manifoldfare cold,

'the hook 90wil1 'engage the sleeve96 `and vpin 95 and will effectively prevent the weight 64 from rising regardless ofthe speed fof the engine. i The valve 54 will "then "causeheat from the exhaust `gases to be appliedV to thel fuel charge flowing through the intakegmanifold regardless of engine speed until the exhaust 'manifold `heats upto a point at whichy thefthermostati'c bar 85 `warps sufiicientlyto release the pin 95 and sleeve 96 i from thehook 90.v From this, time on-the valve A54ivvil1 be freeto fluctuate according tothe flow of exhaust gases to the exhaust manifold.

qIn' theform of "the device illustratedin Figure '4,"the` function is exactly the same as described above,`` but the actualmecl'1anical`emb`odirneht 1 of the idea is slightlydiierent. In thisiform` of the device, the lateralportion or abutment 110 `which 'corresponds {tothe lateralportion 80 above described ispos'itioned so that its lower surface at an i angle to the horizontal and in this latter f 'the piajnfi has, been"i11ustrated.- The plate 114fis provided with'a downward extension 115 'provided with an aperture, not shown, and ahook` 117 is` pivotallymounted onI thedownward extension 115 by means of a pivot bolt 118 extend` ing through an aperture in the hook` and through the aperture in `the downward extension 115.

iThe free 'end"` of the hook `is provided with an" upstanding portion 119 which is "adapted to en- Q gage `with the'pin 95 and'thefsleeve 96 of the -cnstruction described above; curved thermolstatic bar 120 is secured tothe'lower surfaee :of

, the? portion 110` by suitable means `such as the screws `122fand` isisiecured to thehook by a suitable means; such as thescfrew `123. In the con- .structionl illustrated in Figures, it will be obi served that the "th'ermos'tatie bar120 isY curvedl `whenl the engine is cold or until it hasbeen warmed up 'so that this bar 12o is somewhat longer than a straight line passing'between the screw 123 and the `nearest screw 122. `When the engine warms'up the thermostatic bar 120 tends tof straighten out and, thus pull the hook 119 away from the sleeve 96 "so that when the tip fof the hook 119 moves beyond the horizontal axis 1 of the sleeve 95this will cause complete disengagement of the hook 119` fromgthe `sleeve 96 duetothe pressure ofthe exhaust gases against the valve 56 which tends to swing the sleeve 96 upwardly because of `its mounting being pivotally supported at 52. vAs the thermostat cools off and 4when the valve 56 and its associated parts, in-

, cludingthe sleeve 96, return "to the positionillustrated in Fig. 1,the`lhook 119 will engage with the sleeve `96 andthere be no tendencyifor the thermostat to unlatch the hook from the sleeve` is provided onthe plat-e 127. Thislaterally ex.-

`tending portion 125ha'sfa horizontal lower surface and4 isbraced tothe plateiby means of `a singlevertical' rib `123.1` The lplate 127 is provided with a downwardlyfand outwardlyextending por- 'tion130 which carries `atithe` extremity thereof a cylindrical'sleeve 132. i A pin 133 is slidably mounted inthe sleeve 1321and has a' beveled inner end 134 adapted to engage the sleeve `96 `and lockthe weight 6e in its `lowermost position. `A thermostaticjbar `135"has1one end secured to theflowersurface' of the portion 125lby suitable means such as thescrewsvlSZ'and the free end `of the `barpasses `through a slot in the outer` end of the'pin 133, pinslbeing interposed beslot i` i i It will' be observedthatinthe form` of the device illustrated in Figure, the thermostatic bar 135 is operative` upon/changes iin theftemperaturethereofrto move the"l pin 133 throughthe sleeve 132 tobringtheinner end of the pininto position tolatcl'r the weight-64 in its lowermost position and to movethe pin to cause itto releasethe weight and, it will also `be observed that each form `of `the invention as describedrabove serves the purposeof maintaining the weight in its lowermost position to maintain the carburetor heat` valve closed'to force exhaust gases into heat exchanging relationship with the intake manifold until such time as the engine andthe exhaustmanifold thereof have reached a temperature at whichit is no longer necessary to heat theffuel charge being drawn throughthe intake manifold'intothel engine cylinders.

`',Whil'e I haveshown a preferred form" of the tween the sidesf ofthe bar and the sides ofthe deviceifof kthe invention and two `modifications thereoiit is to be understood that the' drawing forming a: partof this application andthe above description does not limit the invention. andthat such changes in the size, shape and arrangement `of parts may be resorted toas 'come within the scope'of the appended claims. Y i. `1 i i i' Havingv now"`describ'ed my invention `)so that ,others skilled in the art may clearlyunderstand the same, what I desire 'to secure'by- Letters Patent islas followstvv 1 l 1. In combination with an internal combustion angina: an intake manifold having` `a heating chamber therein, an exhaust' manifold provided `with f a passage leading to said heating chamber,

and a heat control valve gravity urged toward a said exhaust manifold to circulate through said` heating chambenand urged bythe flow of exhaust gases to a position toprevent said exhaust gases from flowing lthrough `said heatingchamber; a thermostatically actuated latch tomaintain said valve in, position to cause the exhaust gases to ow through` said heating chamber when said engine is below'a 'predetermined` temperature,fsaid latch releasing said valve whenv the engine reaches a predetermined working temperature. r i. 'V w i 2. In combination withan internal combustion engine, -an` intakev manifold having a heating chamber therein, an exhaust manifold provided with apassage leading to said heating chamber, a valve adapted when in closed position to cause exhaust'gasto flow through said heating'chamber and when in open position` to prevent theiiiow4 oflexhaust gas through said heatingchamber urged by the flow of `exhaust gas toward open position, and a weight adaptedto urge said valve toward closed position;` a thermostaticibar secured atone end to a xedi abutment and means l' connected' tothe-opposite end of said thermo- Vstatic bar adapted-fte engage said Weight to tem- V with a passage leading to said heating chamber,

a'valve -disposedwithin said exhaust' manifold j adapted when inA closed position to cause exhaust gas to iiovvI through said heating chamber and when lin :open position to prevent the flow of exhaust gas through said heating ychamber urged by the flow of exhaust gas toward open position,

and a Weight disposed exteriorly of said exhaust manifold and `operatively connected with said valve for urging the valve toward closed position; a fixed abutment on the exterior of said exhaust manifold, a thermostatic bar connected at `one end to `said abutment, a pin secured in said Weight and a hook actuated by said thermostatic bar adapted to engage said pin to temporarily latch said valve in closed position and to release'said pin upon a predetermined rise in the temperature of said thermostatic bar. Y

4. In combination with an internal combustion engine, an intake manifold having a heating chamber therein, an exhaust manifold provided With a passage leading to lsaid heating chamber, a valve disposed Within said exhaust manifold adapted when in closed position to' cause exhaust gas to flow through said heating chamber and When `in open position to prevent the flow of exhaust gasr through said heating chamber urged by the flow 'of' exhaust gas toward open position, and a Weight disposed exteriorly of said exhaust manifold and operatively connected lvvith said valve for urging'the valve towardfclosed position; a platerigidly secured upon the exterior of said exhaust manifold, a thermostat carried by said plate, a pin in said Weight-andalatch member actuated .by said f thermostat vadapted to engage said pin to temporarily `latch said valve in closed position and to release said pin upon a predeter- Y mined rise in the temperature of said thermostat.

5. -In combination with an internal combustion engine, an intake manifold vhaving a 'heating chamber therein, an exhaust manifold provided with a passage .leading to said heating chamber, a valve disposed Within said exhaust manifold adapted when in closed position to `cause exhaust gas to flow through said 'heating chamber and when in open position to prevent the flow of exhaust'gas throughsaid heating chamber urged by the how of exhaust gas toward open position, and a Weight disposed exteriorly of said exhaust manifold and operatively connected with said valve for urging the valve toward closed position; a pin in said Weight, a fixed abutment upon the exterior of said exhaust manifold, a thermostatic barsecured at one end to said abutment, a hook member having an upstanding portion adapted to engagesaid pinactuated by said thermostat to engage said pin to temporarily latch said valve inclosed position and torelease said pin upona predeternriined rise in the temperature of said thermostat.

, 6. In combination vvitlri an internal combustion engine, an intake manifold having a heating chamber therein, an exhaust manifold provided with a passage leading to said heating chamber, a valve disposed vWithin said exhaust manifold adapted When/in closed position to cause exhaust gas to fioW through said heating chamber and whenin open position to prevent the flow of exhaust4 gas through.y saidheating chamber urged vbythe flow of exhaustgas toward open position,

and a weight disposed Vexteriorly of said exhaust manifold and operatively connected With said valve for urging the valve toward closed position; a pin in said Weight, a fixed abutment upon the exterior of saidexhaust manifold, a thermostatic bar rigidly secured at oney end to said abutment, a hook member rigidly secured to the opposite end of said thermostatic bar from said abutment actuated by said thermostatic bar to engage said pin to temporarily latch said valve in closed position and Yto release said pin upon a predetermined rise in the temperature of said thermostatic bar. l

7. In combination with an internal combustion engine, an intake manifold having a heating chamber therein, an exhaust manifold provided With a passage leading to said heating chamber, a valve disposed Withinl 4said exhaust manifold adapted when in closed position to cause exhaust gasto flow through said heating chamber and when in open position to prevent the iiow of exhaust gas through said heating chamber urged by the flow of exhaust gas toward open position, and a weight disposed exteriorly of said exhaust manifold and operatively connected with said `valve for urging the valve toward closed position; a pin in saidv weight, a fixed abutment having a substantially horizontal surface on the exterior vof said exhaust manifold, a thermostatic bar secured at one end to said horizontal surface and extending substantially in alignment therewith,-

and a latch member actuated by said thermostatic bar adapted to engage said pin to temporarily latch saidk valve in closed position and to release vsaid pin upon a predetermined risein the temperature of said thermostatic bar.

8. In combination With an internal combustion engine, an intake manifold having a heating chamber therein, an exhaust manifold provided vWith `a passage leading to said heating chamber,

a valve disposed Within said exhaust manifold adapted when in closed position to cause exhaust gas to how through said heating chamber and When in open position to preventthe ow of exhaust gas through said heating chamber urged by the flow of exhaust gas toward open position,

' and a weight disposed exteriorly of said exhaust manifold and operatively connected with said l valve for urging the valve toward closed position;

a pin in said Weight, a plate rigidly secured upon the exterior of said exhaust manifold, an abutment on said plate, a thermostat rigidly `secured to said abutment, and a latch member carried by said plate actuated by said thermostat to engage said pin to temporarily latch said valve in closed position and to release said weight upon a predetermined rise in the temperature of said thermostat.

9. In combination with an internal combustion engine, an intake manifold having a heating chamber therein, an exhaust manifold provided With a passage leading to said heating chamber,

a valve disposed Within said exhaust manifold adapted When in closed position to cause exhaust gas to flow through said heating chamber and When in open position to prevent the flow of exhaust gas through saidheating chamber urged by theflovv of exhaust gas toward open position, and a Weight disposed exteriorly of said exhaust manifold and operatively connected with said valve for urging the valve toward closed position; a plate rigidly secured upon the exterior of said exhaust manifold, an-abutment on said plate, an extension formed on said plate, a thermostat rigidly secured at one end to said abutment and a latching element mounted on said extension actuated by said thermostat to engage 'said Weight to temporarilylatch said -valve in closed position and to release said weight upon a predetermined rise in the temperature `of said thermostat.

e gas to flow through said heating chamber and when in open position to prevent the flow of exhaust gas through said heating chamber urged by the flow of exhaust gas toward open position, and

a weight disposedexteriorly of said exhaustmanifold and operatively connected with said valve for urging the valve toward closed position; a fixed abutment on the exterior of said exhaust manifold, a thermostatic bar rigidly secured at one end to said abutment, and a hook carried by the free end `,of said bar operative to engage said Weight to temporarily latch said valve in closed position and to release said Weight upon a predetermined rise in the temperature of said bar.

11. In combination with an internal combustion engine, an intake manifold having a heating chamber therein, anexhaustmanifold provided with a passage leading to said heating chamber, a

. valve disposed within saidl exhaust manifold adapted when in closed position to cause exhaust gas to flow through `said heating chamber and When in open position to prevent the flow of exhaust gas through said heating chamber urged by the flow of exhaust gas toward open position, and a weight disposed exteriorly of said exhaust manifold and operatively connected with said valve for urging the valve toward closed position; a pin in said weight, a sleeve rotatablymounted on said pin, a fixed abutment on the exterior of said exhaust manifold, a thermostat rigidly secured at one end to said abutment, anda hook carried by said thermostat operative to engage said sleeve to temporarily latch said valve in closed position and to release said sleeve upon a predetermined rise in the temperature of said thermostat.

12. In combination with an internal combustion engine, an intake manifold having a heating chamber therein, an exhaust manifold provided with a passage leading to said heating chamber, a valve disposed'within said exhaust manifold adapted when in closed position to cause exhaust gas to flow through said heating chamber and when in open position to prevent the flow of exhaust gas through said heating chamber urged by the flow of exhaust gas toward open position, and a Weight disposed exteriorly of said exhaust manifold `and operatively. connected with said `'valve for urging the valve toward closed position;

a plate secured upon the exterior of said exhaust manifold, a thermostat rigidly secured at one end to said plate, a hook pivotally mounted onsaid plate and operatively connected to said thermostat, said thermostat being longer than the distance betweenits connections to said plate and said hook` whereby said thermostat will move from one to the other of its two operative positions and move said hook from a position to engage said weight toa position to release said weight or vice versa.

13. In combination with an internal combustion engine, an intake manifold having a heating chamber therein, an exhaust manifold provided With a passage leading to said heating chamber, a valve disposed within said exhaust manifold adapted when in closed position to cause exhaust gas to flow through said heating chamber and when in open position to prevent the flow of exhaust gas through said heating chamber urged by the flow of exhaust gas toward open position, and a weight `disposed exteriorly of said exhaust manifold andA operatively connected with said valve for urging the valve toward closed position; a plate secured to the exterior of said exhaust manifold, asleeve on said plate, a latch pin slidably mounted in said sleeve, a thermostat mounted on said plate and operatively connected with said latch pin to actuate said latch pin to engage said weight to temporarily latch said valve in closed position and to release saidweight upon a predetermined rise in the temperature of said thermostat.

` sTANWooD W. SPARROW. 

